An original cover is attached via original cover closers to a main body of office equipment such as a copying machine, a printer, a facsimile, a scanner. Each original cover closer is a kind of hinge mechanism, of which the layout is as disclosed in JP Laid-Open Patent Application H11-95339: it comprises an attaching member comprising a bottom plate attached to the main body of office equipment; both side plates erected from both sides of the bottom plate; a supporting member comprising an upper plate and both side plates provided to hang down perpendicular to both sides of the upper plate, wherein the supporting member is assembled by rotatably coupling its both side plates to the both side plates of the attaching member via a first hinge pin; a lifting member comprising an upper plate attached to the original cover and both side plates provided to hang down perpendicular to both sides of the upper plate, wherein the both side plates of the lifting member are coupled to the free end side of the supporting member via a second hinge pin, such that the lifting member is rotatable in a direction opposite to the direction in which the supporting member rotates, an actuating member installed between the both side plates of the lifting member; a first slider which is in contact with the actuating member and housed between the both side plates of the supporting member, such that the first slider is slidable; a pressure bearing member provided between the both side plates of the attaching member; a second slider in contact with the pressure bearing member, wherein the second slider is housed between the both side plates of the supporting member, such that the second slider is slidable; and a compression coil spring resiliently provided between the first slider and the second slider.
When such a conventional original cover is opened, internal parts of an original cover closer, which are used for attaching the original cover to a main body, such that the original cover is openable and closable (in particular an actuating member, a first slider, a second slider, a pressure bearing member and a compression coil spring), will have parts exposed to the outside. A user can see such internal parts, so their appearance gives unfavorable impressions. Still further, lubricating grease and oil (as applied onto sliding contact surface of the actuating member and the first slider, that of the first slider and the supporting member, and that of the second slider and the supporting member, as well as onto an area corresponding to the compression coil spring) often smear ends of an original lying outside the contact glass, when the original is put on the contact glass for the purpose of scanning. Still further, when the original cover is attached to the main body in assembly, or detached from and attached to it during repair works, a worker often touches the original cover by hands or grasps it, and in this manner, a problem arises in that his hands are smeared with the grease and oil as mentioned above.